Sealing system for washing machine

ABSTRACT

An automatic washing machine of the type having a pump-motor arrangement delivering pressurized washing liquid to a spray arm. The pump outlet is provided with a seal member which expands into sealing engagement with the spray arm in response to the delivery of pressurized washing liquid therethrough. The pump-motor arrangement is removable from the bottom of the washing tub by moving it outwardly through the tub. The spray arm is mounted in axial alignment with the pump outlet by a support spanning the pump-motor arrangement.

United States Patent [191 Jenkins SEALING SYSTEM FOR WASHING MACHINE [75] inventor: Thomas E. Jenkins, Louisville, Ky.

[73]' Assignee: General Electric Company, I

Louisville, Ky.

[22] Filed: Jan. 2, 1973 [21] Appl. No.2 320,616

[52] US. Cl 239/259, 134/179, 239/264 [51] Int. Cl B05b 3/06 [58] Field of Search... 239/225, 251, 259,

[56] References Cited UNlTED STATES PATENTS 5/1966 Long e tal.l 239/251 x 1 Jan. 15, 1974 Primary ExaminerRobert S. Ward, Jr. Assistant Examiner-Michael Y. Mar Attorney-George C. Atwell et al.

57 ABSTRACT An automatic washing machine of the type having a pump-motor arrangement delivering pressurized washing liquid to a spray arm. The pump outlet is provided with a seal member which expands into sealing engagement with the spray arm in response to the delivery of pressurized washing liquid therethrough. The pump-motor arrangement is removable from the bottom of the washing tub by moving it outwardly through the tub. The spray arm is mounted in axial alignment with the pump outlet by a support spanning the pump-motor arrangement.

8 Claims, 3 Drawing Figures PATENTEDJAN 1 5 mm SHEET a (If 3 PATENT JAN 1 51914.

sum 3 [IF 3 1 SEALING SYSTEM FOR WASHING MACHINE Automatic dishwashers are typically provided with a pump-motor arrangement disposed wholly beneath the tub bottom having a rigid pump outlet extending through the tub bottom into registry with a spray arm. Since the vertical dimension of automatic dishwashers is controlled by normal cabinet heights, the pumpmotor arrangement reduces the size of the wash chamber substantially. In contrast, the pump-motor arrangement of this invention projects above the bottom of the washing tub and effectively increases the size of the washing chamber for a given vertical dimension of the dishwasher.

The rigid pump outlet of the prior art dishwashers is typically equipped with bearing means to rotatably mount the spray arm thereon. In contrast, the device of this invention incorporates a support spanning the pump-motor arrangement for rotatably mounting the spray arm independently of the'pump outlet.

The dishwashers of the prior art typically incorporate a seal of some description between the pump outlet and the rotatable spray arm mounted thereon to reduce liquid leakage and thereby enhance operating efficiency. In addition to its primary function of reducing liquid leakage, seals desirably reduce or eliminate the transmission of vibration from the pump-motor arrangement to the spray arm, accommodate misalignment of the spray arm relative to the pump outlet, allow drainage of liquid in the spray arm at the cessation of pump operation and incorporate relatively simple seal attachment mechanisms. While all of the prior art sealing devices reduce liquid leakage and may provide one or more of these additional advantages few, if any, provide all of these desirablefeatures.

A sealing device similar to that disclosed herein is found in US Pat. Nos. 3,009,470 and 3,064,664. The provision of misalignment compensating devices is found in US. Pat. Nos. 3,l 15,352 and 3,275,334.

It is an object of this invention to provide a washing machine having a seal operative between a rigid stationary pump outlet and a rigid stationary spray arm conduit, the seal being expanded into sealing position by delivery of pressurized liquid therepast.

Another object of this invention is the provision of an automatic washing machine in which a pump-motor arrangement extends above the bottom of the washing tub.

Other objects and advantages of this invention will be apparent to those skilled in the art as this description proceeds.

In summary, one aspect of this invention comprises an automatic washing machine including a tub providing a wash chamber having a tub bottom providing an opening therethrough; a pump-motor arrangement disposed at least partially below the tub bottom having a liquid outlet and a liquid inlet; means sealing the liquid outlet to the tub bottom opening; a spray arm and means rotatable supporting the spray arm on the tub independently of the liquid outlet at a location spaced from the rigid pump outlet; and seal means, between the liquid outlet and the spray arm, expansible in response to passage of liquid therethrough for sealably engaging the liquid outlet and the spray arm and providing a liquid passage therebetween.

In THE DRAWINGS:

FIG. 1 is a partial vertical cross section of a dishwasher embodying this invention, taken along line 11 of FIG. 3 as viewed in the direction shown by the arrows;

FIG. 2 is a view similarto FIG. 1 illustrating the seal in the operative position; and I FIG. 3 is a plan view of the bottom of the washing chamber, certain parts being broken away for clarity of illustration.

Referring to FIG. 1, there is disclosed a dishwasher 10 comprising a cabinet 12 having a door 14 pivoted thereon providing access to a washing chamber 16. The washing chamber 16 is provided by a washing tub 18 having side walls 20, a back wall 22, a top wall (not shown) and a tub bottom 24. The side walls 20 provide spaced ledges 26 for supporting a dish rack 28 for movement into and out of the washing chamber 16. The door 14 includes an inner panel 30 which, in the open position, is substantially coplaner with the ledges 26 to provide a support for the wheels 32 of the dish rack 28.

The tub bottom 24 includes a'well 34 terminating in an opening 36 providing communication between the washing chamber 16 and a compartment 38 which houses the bulk of a pump-motor arrangement 40 comprising an electric motor 42 and a pump 44. The pumpmotor 40 may be supported from the cabinet 12 or tub bottom 24 in any suitable manner. A preferred suspension technique is discussed more fully hereinafter. The pump 44 includes an inlet 46, an impeller 48 and an outlet 50. The casing of the pump 44 is typically metal or plastic.

The tub bottom 24 slopes generally toward the well 34. It will will be noted from FIG. I that the pumpmotor arrangement 40 projects above the trace 52 of the tub bottom 24. It will accordingly be seen that the tub bottom 24 has been dropped relative to the pumpmotor arrangement 40 thereby increasing the vertical dimension of the washing chamber 16.

' Sealing the pump inlet 46 and the pump outlet 50 to the tub bottom 24 is a rubber boot 54 and peripheral sealing means 56. The rubber boot 54 includes a humped portion 58 extending over the enlarged end of the motor 42 and over the pump 44. The boot 54 includes a well 60 and troughs 62, 64 (FIG. 3) draining into the well 60 and providing a path of liquid return movement from the tub bottom 24 to the pump inlet 46. The outer periphery of the boot 54 includes a reverted lip receiving one leg of a band 66 of generally U-shaped cross section. The band 66 presses the outer periphery of the boot 54 against a generally circular rubber seal 68 placed in the tub well 34. Maintaining the band 66 in position is a pair of generally semicircular members 70 of wedge-shaped cross section. The members 70 are disposed between the tub bottom 24 and the barid 66. Suitable screw adjustments (not shown) may be provided to draw the members toward each other and therebypull the band 66 downwardly to compress the seal 68 against the boot 54. The pump inlet 46 is desirably threaded onto the pump housing and accordingly captivates the boot 54 therebetween to provide a seal around the inlet 46. It will accordingly be apparent that there is provided a suitable seal between the wash chamber 16 and the compartment 38.

A preferred mode of supporting the pump-motor 40 involves the use of the band 66. As will be apparent from a comparison of FIGS. 1 and 3, the band 66 is exposed to the pump-motor 40 through the major part of the perimeter of the band 66. As shown best in FIG. 3, a pair of shelf-brackets 72 are secured to the band 66 and supportably receive a pair of projections 74 extending from the housing of the pump-motor. It will be apparent that the shelf-brackets 72 support one end of the pump-motor 40. Supporting the other end of the pump-motor 40 is a cradle 76 secured at opposite ends thereof to the bracket 66. It will be readily apparent that the pump-motor 40, the support means comprising the elements 72, 74, 76, the band 66 and the boot 54 comprise a unit-handled assembly which may be installed from inside the wash chamber 16. The clamping members 70 may be manipulated from within the pump-motor compartment 38.

The inner periphery of the boot 54 is captivated and sealed against the pump outlet 50 by a collar 78 threaded thereon. The collar 78 also captivates an expansible seal 80 against the outlet 50. It will accordingly be apparent that there is provided means for sealing the pump outlet 50 to the tub bottom 24 thereby avoiding undesirable liquid leakage.

Positioned above and spaced from the expansible seal 80 is a spray arm 82 which is desirably of the balanced type. The spray arm 82 comprises, as major components, a stationary conduit 84-, means 86 supporting the conduit 80 from the tub bottom 24, a rotatable spray arm hub 88 and a pair of spray arm sections 90. 92.

The stationary conduit 84 may be of injection molded plastic and comprises an annular exterior bearing support 94 and an exterior annular recess for receiving the support means 86. The support means 86 comprises a metal, preferably stainless steel, shell 96 having a humped portion 98 overlying and generally corresponding to the shape of the humped portion 58 of the rubber boot 54. The upper surface of the shell 98 is generally upwardly convex to shed water toward the exterior of the tub bottom wall 34. The support means 86 includes a plurality of arms 100 projecting horizontally from the shell 96 for securing the support means 86 to the tub bottom 24. To this end, there are provided a plurality of spacers 102 between the arms 100 and the tub bottom 24 with suitable fasteners (not shown) residing along fastening axes 104 for attaching the arms 100 to the tub bottom 24 through openings 106. As shown best in FIGS. 1 and 2, the bottom edge 108 of the shell 96 is disposed above the trace 52 of the tub bottom 24 thereby providing a generally circular slot for draining water from the wash chamber 16 into the troughs 62, 64 of the rubber boot 54.

It is recognized that a break or tear in the boot 54 would permit finger access by a curious child or other person to electrical components beneath the boot, however, the shell 96 serves the further advantage ofa rigid barrier or shield over the boot 54. Inadvertent puncture of the boot 54, as might be caused by a sharp knife or other instrument dropping from the racks thereabove, is also prevented by the presence of the shell 96.

The rotatable spray hub 88 includes a collar 110 having an inner bearing support 112 thereon for captivating a plurality of ball bearings 114 against the bearing support 88. The bearing surfaces of the supports 94, 112 may be metal clad as desired. The hub 88 includes an intermediate section 116 threaded into the top of the collar 110 and having a cap 118 threaded thereinto. The intermediate hub section 116 includes a plurality of openings 120, 122 providing communication to the spray arm sections 90, 92 respectively.

The spray arm sections 90, 92 provide a substantially balanced spray arm and may be made of sheet metal or plastic. The sections 90, 92 are captivated to the hub 88 between the cap 118 and the intermediate hub section 116. The sections 90, 92 include a plurality of spray openings 124, 126 and suitable symmetrical reaction nozzles 128, 130.

As previously stated, an important feature of this invention resides in the expansible seal 80 and its cooperation with the spray arm 82. FIG. 1 represents the inoperative position of the dishwasher 10, as when the door 14 is open and the rack 28 is in the process of being loaded. The expansible seal 80 assumes its relaxed position of FIG. 1 in the absence of pressurized liquid being delivered from the pump 44. As suggested previously, the expansible seal 80 provides a plurality of substantial advantages such as adequately minimizing liquid leakage between the pump outlet 50 and the spray arm 82, isolating pump vibration from the spray arm 82 and thereby minimizing operating noise, allowing drainage of wash liquid in the spray arm 80 onto the boot 54 at the termination of the wash cycle, allowing misalignment of the spray arm 80 relative to the pump outlet 50 during the process of manufacture, and allowing the use of relatively simple clamping techniques.

I claim:

1. A dishwashing machine comprising a tub providing a wash chamber including a tub bottom having an opening therethrough;

a pump-motor arrangement disposed at least partially below the tub bottom having a liquid outlet and a liquid inlet;

means sealing the liquid inlet and outlet to the tub bottom;

a spray arm and means rotatably supporting the spray arm on the tub independently of the liquid outlet at a location spaced from the rigid pump outlet; and

seal means, between the liquid outlet and the spray arm, expansible in response to passage of liquid therethrough for sealably engaging the spray arm and providing a liquid passage therebetween.

2. The washing machine of claim 1 wherein the seal means has one end attached to the liquid outlet and the other end spaced from the spray arm until passage of liquid past the seal means.

3. The washing machine of claim 1 wherein the seal means comprises a liquid conduit having one end attached to the liquid outlet, another end spaced from the spray arm until passage of liquid therethrough and an intermediate flexible section expansible upon passage of liquid through the conduit.

4. The washing machine of claim 3 wherein the pump outlet is rigid.

5. The washing machine of claim 1 wherein the spray arm support means comprises a rigid shell and means securing the shell to the tub bottom.'

6. The washing machine of claim 5 wherein the shell is convex toward the wash chamber.

7. The washing machine of claim 5 wherein the lower edge of the shell is spaced above the trace of the tub bottom.

8. The washing machine of claim 5 wherein the rigid shell substantially covers the tub bottom opening. 

1. A dishwashing machine comprising a tub providing a wash chamber including a tub bottom having an opening therethrough; a pump-motor arrangement disposed at least partially below the tub bottom having a liquid outlet and a liquid inlet; means sealing the liquid inlet and outlet to the tub bottom; a spray arm and means rotatably supporting the spray arm on the tub independently of the liquid outlet at a location spaced from the rigid pump outlet; and seal means, between the liquid outlet and the spray arm, expansible in response to passage of liquid therethrough for sealably engaging the spray arm and providing a liquid passage therebetween.
 2. The washing machine of claim 1 wherein the seal means has one end attached to the liquid outlet and the other end spaced from the spray arm until passage of liquid past the seal means.
 3. The washing machine of claim 1 wherein the seal means comprises a liquid conduit having one end attached to the liquid outlet, another end spaced from the spray arm until passage of liquid therethrough and an intermediate flexible section expansible upon passage of liquid through the conduit.
 4. The washing machine of claim 3 wherein the pump outlet is rigid.
 5. The washing machine of claim 1 wherein the spray arm support means comprises a rigid shell and means securing the shell to the tub bottom.
 6. The washing machine of claim 5 wherein the shell is convex toward the wash chamber.
 7. The washing machine of claim 5 wherein the lower edge of the shell is spaced above the trace of the tub bottom.
 8. The washing machine of claim 5 wherein the rigid shell substantially covers the tub bottom opening. 